In many chemical and biochemical studies, it is frequently necessary to distribute the reagent or solution precisely and rapidly to multiple containers. In one presently used laboratory system, the reagent is dispensed through multiple pipettes arrangement and corresponding multiple tubings. This system is not only cumbersome and slow to operate, but also presents a sterility problem since each time a different reagent flows through the pipette, it must be thoroughly sterilized for different reagent dispensation. Where rapidity and accuracy of measurement or analyses are required, such systems are grossly inadequate.
Another prior art system for transferring liquid between containers is described in U.S. Pat. No. 3,687,632. The system described in this patent comprises a flat movable platform for receiving two trays, each provided with a row of test tubes or containers. This system is designed so that an accurately measured amount of liquid is transferred from a first group of containers in a row on one tray, to a second group of containers in a row on the second tray, while a reagent is being added during the transfer. The platform moves linearly to properly position each container for aspirating fluid from a container and transferring to another container. The movement of the platform is controlled by a rack and pinion.
In another prior art patent, i.e., U.S. Pat. No. 4,681,742, there is described a fluid dispensing machine for transferring liquid to and from the wells of an assay tray. The machine includes a horizontally translatable table and a vertically translatable head assembly. Translation of the horizontal table is provided by a stepper motor through a pinion gear connected to the motor and to a rack. Translation of the head assembly is provided by a stepper motor by a similar pinion gear-rack arrangement. A plurality of liquid dispensing manifolds are used for dispensing liquid into the wells of the assay tray.
Thus, as it can be seen, the prior art fluid dispensing systems used to carry out biochemical reactions are difficult to construct, cumbersome to operate, require complicated sterilization procedures and, in general, are very expensive.
Accordingly, it is an object of this invention to provide a fluid dispenser for use in conducting biochemical reactions, immunoassay and other chemical reactions wherein the dispenser is characterized by its simplicity of construction and more efficient operation compared to the prior art systems.
It is a further object of this invention to provide an automatic fluid dispenser which is capable of introducing fluid through a single pipette into the wells of a multi-welled dish or assay tray.
It is yet another object of this invention to provide such automatic fluid dispenser which dispenses predetermined and precise amounts of fluid rapidly using a single disposable tubing and pipette, thus eliminating the need for sterilization or at least simplifying sterility procedures.
The foregoing and other features of the present invention will be more readily appreciated from the ensuing detailed description of the invention by reference to the accompanying drawings.